Universal relay



April 23, A1929. w. K. HOWE UNIVERSAL RELAY Filed July 19. 1920 4 sheets-sheet Y www@ TIL April 23, 1929.

w. K HowE UNIVERSAL` RELAY Filed July l. 1920 prl"`23, 1929. w. K. HowE UNIVERSAL RELAY Filed July 19, 1920 4 sheets-sheet 11s/Wag BY 'AT oRNEY April 23,1929. w, K HowE I 1,710,664

y UNIVERSAL RELAY Filed July 19, 1920 4 sheets-sheet 4 NV NT WTTORN- Patented Apr. 23, U N l lf' E S T 'if WINTHROP HWE, CSCW' SIGNAL COMPANY, GF

.application filed Enly 19,

This invention relates to alternating cnrrent relays nscd in. raibiay maling f-iystenis. rllhe objects et 'the inventifni are to improve and siinpli'ty the constrncti n el rlternating current relays, increase the e'lliciency a nd reliability of their periorinain-e, and to provide an arrangement and organizntion ot parts which can be readily convert-d or adapted to snit the varicfcs working conditions and eonirelnents ordinarily tonnd in practice. Various other objects andadvantages of the improved relay will be pointed ont as the description progresses.

in describing the in x'fention in detaila reiference will be made to the :accompanying drawings, in which like reference characters designate t coi-responeineY tarts in the several vievvs and in which K Figure 1 is a front view ot one side o 'the relay, with part ot the casing;` broken away;

.li 2 a iront view or another side et the rlelay7 with the lower part or the device in Vertical section;

Fig. 3 is a horizontal section through the relay taken substantially on the line 3 3 in Fig. 1;

Fig'. e is a horizontal section through the stator and rotor, taken snbstaA tially on the line in Fig. 2;

Fig. 5 is a vertical section through the stator taken substantially on the line 5 5 in Fig. 1;

Figs. 6 to 11 are detail ieivs of parts otb the device;

Figs. 12 to 14 are perspective views, dia- `gmniniatic in their nature. and having soine parts broken away or omitted7 which show dillierentarrangements of the contacts and operating` mechanism; and

Fig. 15 is a detail sect-ion oi an insnlatec stud 'for the contact fingers.

The parts ot the relay are supported and enclosed in e bofilike casing` which is niade np ot a skeleton framework, comprising a base 1.I corner posts 2, and upper cross ineinbers 3; a top plate or panel l.) of slate? porcelain or similar insulating material, 'which iastened to said 'framework by screws e; and lglass side Walls 5 fastened to 'the framework by bezel rings 6 provided with suitable gas-- kets.

rEhe relay is constructed so that the parts may be assembled in different ways to make np the various con'lbinations or organizations of ordina 'il f rccnired in practice in l l m l ra 'Way signalnnby systems. ihe construction il. smated provides `-r three-position or twoosi-.ion operation, with either a direct-conectcd rotor or a. pinion-and-sector connecrn. and with various contact arrangements. in the three-nosition operation, the rotor7 yhich in relays ot this type constitutes the )enter element? inay be driven in either directie-n, depending' npon the Way in Which its operation windings are energized.; and consequently, seine contacts may be closed when the relay is emrgized in one Way, and others when it is energized in another Way, these ditterent groups oit contacts being conln'lonly erined the norinal and reverse contacts. In `l` e two-position operation, the rotor is driven n one direction and only one group of conct-s are closed nnen the relay is energized. ln both the threeposition and tivo-position operation, the contacts ot the relay have de- -Uzed positions to n'hich they are biased by suitable connterweighting ineans and tend assrnne when currentl is cnt orf Yfrom the relay.

The parts of the relay are conveniently grouped and described separately as follows The stator and rotor construction of the operating inotor' the contacts or circuit controlling devices; the connterweighting means; and the relay movement connecting` the rotor to the contacts.

lie operating inotor comprises a Innlt-ipolar stator a shell-type rotor, and a fixed core within the rotor. These parts are car ried by a detachable bottoni plate 7 fastened by screws 8 to the base 1 of the niain 'traine- Work ot the relay. This bottoni plate 7 has an integral hollow core support 9 on which the laniinee 10 ol the core are pressed. The stator is inade np of a circula-r yoke 11, and ilnrality of pole pieces 12. This stator 11 consists or" a stackingof laminaJ in the rorni ot split rings having their ends 'e 'ly separated, the joints of the several being staggered, as shown in Figs. 1 and d. Anole brackets 18 are riveted to the ends stator yoke 11 and are connected by elainp screivslll (see Fig. 1) so that the yoke may be contracted. Each ot the pole pieces 12 consists oi a stacking ot T-shaped laminas riveted together an l having a butt joint with the yoke 11.

frere The whole stator, including the yoke 11 and the pole pieces 12, is supported by the walls of a rotor casing which comprises upper and lower' ectagonal shells 15 and 16 (see Fig. of brass or other suitable non-magnetic material. and a cover 17 fastened to the upper shell 15 by tap bolts (see Fig. 2). rl`he lower shell 16 fastened to the bottom plate 7 by screws having their heads countersunk in rccesses in said bottom plate. The stator is disposed between the shells 15 and 16, with suitable interposed gaskets and said shells are clamped together' by a number of long screws 18 surrounded b v suitable bushings. These screws 1S pass between the tips of the pole pieces 12, these tips being slightly recessed to receive said screws and bushings see Fig. 4). The coils 19 for the stator are formwound, and are pnt in place before the pole pieces 12 and the stator yoke 11. are assembled. By tightening the screws 14, the yoke 11 may be cont 'acted to form a tight joint with the pole pieces 12 and hold all the parts rigidly together. The alternate coils 19 are connected in series. as shown in Fig. 3, to form a twophase winding, comprisingr a local winding and a track or line winding.

The rotor comprises a hub 2O and a shell 21, the shell being made of brass, aluminum or similar light and electrically conducting material. The hub 20 is connected to a rotor shaft 22 by a friction clutch and lost-motion device shown in detail in Fig. 6. This device comprises a d iving member 23 loose on the shaft 22 and having two radial arms which engage lugs 2On integral with the hub 20. On each side of this member 23 is a washer 24 having an integral tongue fitting into the slot or keyway 25 in the rotor shaft 22, and between said member 23 and each washer 24 is a friction disc 26, these parts being pressed together by a spring 27. The inner washer 2liv bears against a shoulder on the shaft 22, and the rotor hub 2O may turn freely on said shaft except as its movement is limited by the engagement ofthe lugs 2On with the arms of member 28 and friction between member 23, washers 211, and the friction disks 26.

Then the stator windings are energized with alternating current having the proper phase displacement, the rotor is caused to r0- tate in one direction or the other, depending upon the phase relation of the currents in said windings, in much the same way as the well known induction motor operates. Assuming that the rotor turns in the counter-clockwise direction as viewed in Fig. 6, the lugs 2Oa engage the arms of member 23 and drive the shaft 22 and actuate the circuit controlling Yilen'ients of the relay. During this operation the movement of the parts is comparatively quick, and the friction clutch is employed so that the rotor may, if necessary, continue its movement and overrun slightly in opposition to the friction of the clutch, when the circuit coi'itrolling elements stop, thereby avoiding shock and ar to the mechanism.

Upon deenergization of the relay, which in practice is usually done by cutting ofi' the supply of alternating current to one of the stator windings while maintaining it on the other or local windings, the parts ofthe relay, including the shaft and the rotor 21, are returned to their neutral or biased position, by the counter-weighting means hereinafter described. This return movement drives the rotor 21 and its shaft 22 backward, that is, in the clockwise direction in the instance assumed; and during this backward movement the rotor acquires considerable momentum on account of its speed and weight. After the circuit controlling elements of the relay come to a stop in the deenergized position, the rotor may continue its movement for part of a revo lution, and one of the stator windings being energized, the rotor is gradually braked and brought to rest by the eddy currents induced in it by this winding, and also by the friction between the hub 2O and shaft 22. Thus, the momentum of the rotor is absorbed and does not tend to rotate the shaft 22 beyond its biased position and produce the objectionable bobbing of the contacts which often occurs in practice when the rotor is directly connected to its shaft and the circuit controlling el ements.

The rotor shaft 22 is arrznged vertically and is supported in upper and lower jewel bearings. To avoid cracking or injury of the jewel in the lower bearing on account of shock or jar, the shaft 22 is spring supported, as best shown in F ig. 9. The lower end of the shaft 22 is bored and counter-bored to three diameters. A ring jewel 28 lits in the largest diameter bore (the edges ol' the shaft being spun over to hold this jewel in place) a cap jewel 29 lits loosely in the next size bore; and a small spring 30 is located in the smallest bore. A flanged stud 31 is pressed into a hole in the bottom plate 7 and has an integral. pol' ied bearing pin 31, with a rounded end, which passes through the ring jewel 28 and bears against the cap jewel 29. The spring 3() absorbs the shocks and jars sometimes occuring in service or shipment, and thus protects the cap jewel 29 from cracking or other injury.

The upper bearing for the rotor shaft comprises a flanged bearing pin $32 set into the upper end ot `aid shaft (see Fig. 8) and a ring jewel 33 fitted into a recess in the cnd of a screw 34,-, the edges of said screw being` spun over to hold the jewel in place. In the direct-connected type of relay (shown in Figs. 1 and 2), the screw 341, with a suitable jam nut, is mounted in a cross member fastened to the upper ends of two standards 36 which are formed integral with the cover 17 for the rotor caf t 11i the pinion-andsector type (shown in Figs. T and l0), this ISU connections, comprise a clip 55 clamped under the nuts holding the finger on its insulated studs 39; a pigtail 56 consisting of a flexible copper strip, a braided band, or the like, which is riveted and soldered, or otherwise fastened, to said clip 55,-, and an angle bracket t7 attached to a binding post B in the same way as the bracket 5st, the other end of the pigtail 56 being secured to this brach-c' o7 by a screw, or in any other suitable way.

An additional middle row of binding posts is provided, as shown in Fig. l, to accon1modate additional pigtail connections, when required, as for example, when there are n n-e than two electrically independent fingers under the two regular pigtail or heel posts. Additional pairs of binding posts B1 and B2 are fastened to the top plate I), and to each of these posts is fastened a` bracket 5S havii a terminal clip 59 for connecting' the lead wires (not shown) for the local and track windings of th-e stator. The contact carrier C is preferably grounded to the frame of the relay by a flexible connection (it) of braided copper or the like, as shown in Fig. 2, so as to protect the contacts from lighting.

The relay movement, constituting the operative connection between the rotor Qi and the contact carrier C, comprises a hanger Il. fastened te the underside of the carrier bar C by two capstan-hcad screws Gl, said hanger having a ridge between said screws bearing against the carrier bar C, so that the hanger ina;Y be adjusted back and forth with respect to said bar. In one construction, l and 13), this hanger I-I is shaped like an inverted U; in another form (Fig. lll) like an inverted Y; and in still another form (i g 12) which is designed for two-position. operation, the hanger has only one arm. he lower ends of the arms of the hanger H are bifureated and carry revoluble rollers (32. These rollers G2 engage opposite sides of a larger roller 63. In the direct-connected type, Figs. l, 8, l2 and lst, this large roller (i3 is journaled on an eccentric axis bet veen two jaws integral with the rotor shaft 22. In the pinion-and-sector type, Figs. 7 and 13, the roller 63 is carri-ed by an auxiliary' operating shaft G4 extending` parallel with the rotor shaft Q2 at one side thereof, said auxiliary sha-ft being` mounted on jewel bearings, the same as the rotor shaft, supported by the cross member and the cover 172 (See Fig. 7.) The rotor shaft Q2 drives the airxiliary shaft (ill through a pinion 65' and a sector GG fixed to said shafts respectively.

If desired, adjustable screws G7, with enlarged heads and suitable lock nuts, may be threaded into the standards 36, as shown in F ig. lil, so as to provide stops against which the rollers 62 may strike and thus limit the movement of the carrier bar C. In two-posi tion operation, one of these screws 67 may he advanced far enough to form a back stop for .e deenergixed condition coiuitriution shown in is rn'ovided by a mein- A member 35, and ar member (not cross member pn therein for the carrier bar C ir of the relay. In

I the back s.

int ral 'i Cong firm lhe roller tir. u/ztcrwer'fy/Lf It/. 'ilwo rangements of counterweights for three-pos. i on operation are illustrated, one acti g directly on the rotor shaft` 22 (Figs. l and or the auxiliary shaft (il (Fig, i3). and the other directly on the carrier bar C (Fig. il). In the first construction, a horizontal counteiwviight shaft 70 is mounted on pointed trunnion pins 71 fastened in lugs 72 ii'itegral with the cross member 35, said trunnion pins being held in said lugs by small trans-'verse screws gripping said pins. This shaft 70 has a :-iect1o1slia.1' ed arm 73 integral therewith, in which are a plurality of holes; and e iumber of weights 74 re fastened to s l a i3 in different positions by a bolt :ing through one of said holes. Also carried by the sha tt 7() are two pairs of arms and between each pair of these arms is pivot: lly mounted a small roller 7G. The rollers 7G be r against rollers 77 carried by pairs of arms 7S extending radially from the rotor shaft or the auxiliary shaft (34.-, as the case may be. The parts are shown in Figs. l, Q and 13 in the deenergized or biased position. i t' the rotor shaft Q2, or the by changing the number of the weights 74,'

or by fastening them in different holes in the arms 73, thc latter adjustment varying the lever arm of said weights with respect to the axis of the shaft 70.

In the other arrangement of counterweights shown in Fig. la, a lifting bar fastened to the carrier bar C, and this lifting bar has adjustable stop screws Sl, with suitable lock nuts, screwed in it near each end. Each of these screws Sl engages a weighted arm S2 which is oirotallj,Y supported at one end in a stirrup 82:3 fastened tothe top plate I). These w ightei arms S2 normally rest upon horizontal tie ges ol' stop brackets 84 which are fastened to the top plate P. The weighted arms are provided with a hole and a bolt by means of which additional weights 85 may he attached. As the carrier bar C is rocked in one direction or the other, one or the other of the weighted arms is raised, thereby creating a bias tending to return the :arrier bar C to its neut 'al or deenergized position. In this construction the counterweighting' is varied by changing the number and thickness of the additional weights 85.

militie/1 5 Wear occurring in the pivot 'hearings or the rotor shalt will not lend on account ol this vert'imil airaiigenient ot the shaft7 to Change perha result iii the rube rotor on pole pieces oif the e vertical arr: igenieiit of the rotor L 'fs the nialriiig of an organization occupy a limited .space7 cient clearane s and the delhe pointthe rotor Carrier a depending; ai'ni one i axis ot said earriel bar, th vided with a bo t i i L tring support nu er or vue L biael et lo a ininiiniiiii, and also (Loes t require any liioiieatioii.

C so

ii since the device vwill in practice at irregular intervals and may ne necessari,Y amount oli liibrioa i, L s. a biaciiet siiiiila to lin proj bar C, and iii said carrier bracket 8f3 is used ips niay receive too iniieli.

Weights added to obl l bearing ot this type will not En connection Wit i di iiai l atl'ected by the unies or .i 'to iiiai ance elav I""lt l f bed7 Wl ieli relays iu railivaj.y systems are orten is previousl)7 eiiplaine-d, the vision 'l'oi' the rotor ob 'lates in 'Jeivels oy Careless handling r clriiistruetion provioes Wide e adi'fantages o'i r suri'aee area o it it the amount ol [lui:

it is o ii o, Y ciiratelT the Y i 1f n i.

snait, and, roi

Vfastened by rivers e" other the iiiotor sli@ i l?! to iiiove ove a scale 9i 'las 17 oli the rotor casino'.

im i UT, i i u o in m: 0 d( lutter il (JUJlLQb O1 dell, L indu 'iiie iMCLt/illll bw i il'. r .1 l L A y A c: .u units. the pointer UO ma.; iiote'l that in the particular conconnection withtheoseilhiti illistraed, Hui: a its upon prae- Aii'l'ire iii l f on 7 vv pole pieces, is not e 'i' and i3).

iiiiioiig the advantageous tentures alqage ilu); i'oiii distinctive troni one enirule t cireuiiiteieiioe or the rotor,

invention, it will be observed taiigulir shape ot the relai7 aords a -deiifidod railway signaling "elays7 and space economy when it is required ii 'fifacli circuits this leakage several of the relays together on a she eeause it assi iii a cabinet. All of the Wiring coiiiiections s isc displacement iii the are iiiade to binding posts on the top o' the l0 iv slings in this coi ection relay, and this enables the several relays to 13 p that the multi-polar stator be placed Close together. aii Lion embodying this iiiveii* All of the niovinU )arts vitli the ezee'otioii tion iern'iits lai-sier air aps and .Greater clearc n -l l 1 L n2 ne l of the rotor are readil i insoecteu ai ivitl out iovi'erino` the eine ent )erlo 7 l .es

the relay. The coils olf the stator fe outside of the rotor easing); or -i so that .it the compound {Witli l ed in accord the glass side Walls. The rotor closed in a protecting' easing, so t other foreign substances eaiiiio or drop into the air gap around I n i coils arel iniX regna irevent its arooer o eration. Fur ance with Well kiioivii oraetice should sollten AL 1 [I l i since the rotor is arranged to ti anu` novi' or dripa it cannot into the rotor tical axis there is practically rio Y' and interi vitli the inoveinent of dirt to pile up iii the air gap a rotor. Sonie clearance is of coursaround the rotor shaft Where through the cover plate i7;

the

Y visions are inade to facilitato )ect-ion and repair oi the i itil (i t Tlf .e sereivs and disconiiec is pi'eierably i'nade smaller than thb around the rotor, so that partie-les U v Y 1 l .Y -f l the cieee-sgi; s he top plate i .li together or the like able to get into the rotor tesi-iig h the el t organization, be

around the shaft will not be enough to ieu oli i lstui'b lie operating;

stiel; the rotor. The aine aroteetioii is pi'oniorhanisiii. Likewise. by taking; out the i bottoni plate i7 -edily detaclie i ietion also permits trie insertion type o? iioveinent in the saine ease.

vided for the pinion and sector (see Y) so that there is no opportunity for 'foreign ined', ter to lodge in the teeth or otherwise obstruct free movement oiC the pirtsa l'iilievvise any associated l f l lie re o. a unit,

6 autres@ The various parts of these units may also be readily taken apart, as will be obvious.

The circuit controlling part-s of the relay are organized so that they may be readily changed and adapted for the dillercntV requirements found in practice. The use ot a contact carrier with lingers projecting in opposite directions from both sides, gives a larger contact capacity in the same space and also facilitates making up some of the peculiar' Contact combinations required. The front and back contacts 49 are adjustable up and down with respect to their cooperating` contact lingers. This adjustment, when once made, is permanent and cannot be accidentally or carelessly changed from the outside of the relay, as for instance, by tighteningI the nuts on the binding posts. The whole contact carrier C may be adjusted by the sci-cn s l with respect to the rotor shal' t and the operating mechanism associated therewith.

The operating connections between the ro* tor and the contact carrier C is obtained by the cooperation of rollers merely having rolling contact with each other, rather than by a link or similar connection, so that friction is `greatly reduced and there is less chance for `derangement or bindingl of the parts.

Other detail features of the construction which add to the accessibility of the parts, decrease the cost ot manufacture and asseinbling, and improve the performance oil: the device and its adaptability to the varying and enacting conditions found in practice, will. be c vident without detail explanation.

lVhat I claim as new and desire to Letters Patent of the United States, is

l. A relay comprising a box like casing; having glass side walls and a top plate of insulating material removably fastened thereto, a pivotally supported rocking carrier bar supported by the top plate, contact fingers attached to the carrier bar and insulated 'therefrom,liXed contacts cooperating witl said lingers also supported by the top plate, a bottom plate removably fastened to said casing', electroanagnetic means in the lower part of the casing supported wholly by the bottom plate for operating said carrier bar, and means including members having operably operating contact with one another for operatively connecting` said rocking` carrier and electro-magnetic means, whereby either the rocking carrier bar or the electrosmagnetic means may be separately removed from the casing.

2. A relay comprising a box like casing` having glass side walls and a top plate of insulating material., circuit controlling means` in the upper part of the casing supported wholly by the top plate and removable therewith and including a pivotally supported carrier bar supporting contact lingers insulated therefrom, an electro-magnetic motor in the lower part of the casing for actuating said cirsecure ijf cuit controlliiw means, said motor being wholly carried by the detachable bottom plate, and means including members having separably operating Contact with one another' for operatively connecting the motor and the circuit controlling means, whereby either the top plate with the circuit controlling means or the bottom plate with the motor may be separately removed.

3. A relay, comprising a box like c: sing having glass side vv ills, a top plate of insulating` material remo-'ably fastened to said casing, circuit eontixfhig means in the upper part of said casingv supported wholly by the top plate, a bottom plate removably fastened to said casing, a motor in the lf. ver part o t the casing wholly suinicrted by said bottom plate and including :i rotor supporte-:l on a if'ertical axis, and quick detacnablc ans operatively connecting said circuit co rollingni vans to the motor comprising parts merely bearing a 1 ,zt each other.

A relay for railway comprising, a shaft "or drivi sari i ne said sha i f nling coopera Yn ca ch other.

5. ln a relayy for railway signaling purposes, the combination of a shaft, electro-ref turning said shaft, a roliu orted by said shaft,y and pivo'laily supported circuit centri'illing means havii-mrollers seein-cd thereto and engaging e sides of said lirst mentioned roller. (i. ik relay for ailway signaling purposes coniprisin'", i i', eleetre-responsive n' 'sans for opera sa snaft, circuit controllingr operatively conm-,cti ng calling purposes o-rcs:ponsive deand means for termincd position g' rollers rolling agalnst La means, and means for l said shaft to said circui controlling means including a roller cccentrically supported 'from said shaft, said shaft and roller being constructed so that the axis of the sha tt passes through sai d roller.

7. ln a relay for railway signalling purposes` the combination of a casing consisting of a tubular transparent portion having an end wall removably secured to each end thereof, a circuit controller wholly supported by one end wall including a member for operatingthe same, and an electro-rcsponsive dcvice wholly supported by the other end wall and including an operatingy member, said circuit controller and lectrt)srf\sponsivc device being so secured to their resp ctive end walls and having;- their cooperating operating meinbe so constructed that operation of said elentro-responsive device causes its operating men'iber to engage the operating member of said circuit coinroller so as to cause operation of said circuit controller, whcreby replacement of either of said end walls after haring` been emovcd rc-establishes the operating coniieclion between said controller and device.

llU

Iii

erative engaging connection between said member and said hanger.

20. A Contact construction for relays comprising, in combination with a panel of insulated material having a non-circular raised ridge on its upper surface surrounding a hele in said panel, a post having a similar non-circular head contained in said hole with its head against said ridge, a clip between said ridge and head Cooperating with the outside face of said head and the outside face of said ridge to prevent turning of the post in the hole, screw threaded means on the lower side of said panel for holding said post on said clip and said clip about said ridge, for preventing removal of said post trom the ton, and a stem carrying a contact piece at its lower end adjustably supported by said post.

21. In al relay for railway signalling purposes, the combination of a shaft, electro-responsive means for turning said shaft, a roller ecoentrically supported by said shaft, and pivotally supported circuit controlling means having rollers secured thereto eng ing opposite sides of said first mentioned ia ler, the parts being so proportioned that the roller supported by said shaft lies in the axis oit said shaft.

22. A relay for railway signalling purposes comprising, a shaft, an electro-responsive device for driving said shaft, and means for biasing said shaft to a predetermined posin tion including a roller having its axis disposed eceentrieally with respect to said shaft, the parts being so proportioned that the axis of said shaft passes through said roller.

23. A relay comprising, an open frame work, a top plate of insulating material detaehably secured to said frame work, a bottom plate, circuit controlling means ineludinr a plurality of Contact lingers and insulated contacts supported wholly by the top plate and x ano\.\able therewith, and an eleetro-re sponsive device supported by the bottom plate, said circuit controlling means and said electrfi-responsive device being operatively c ;nnected by engaging rollers lsupported by the respective devices, the parts being so proportioned that the roller supported by said shaft lies in the axis of said shaft.

A relay for railway signaling purposes comprising, a vertically disposed shaft, an electro-responsive device for driving said shaft, cirruit controlling means pivotally supported about a horizontal axis, a roller ec cci if'ally supported by said shaft, and anot ir roller supported by saidoircuit controlling means, said rollers being in contact with each other and forming an operative connection between said shaft and said means.

25. it contact construction for relays comprising, a panel of insulating material havf' a hole therein, a raised, plane topped, je of non-circular eonlguration around i l hole, a contact post in said hole having an enlargement of non-circular configuration, a separate member receiving said post 'and io' non-circula r grooves in its lower and aces for locliingly engaging the outwe of said ridge and the outside face of enlargement, and a nut on the lower end l po: l for preventing said post being A id and in turn preventing it from being turned.

In testimony whereof I have aflixed my gnature.

VINTl-IROP K. HOVE. 

